Seventeen of the Metro’s turns were deemed to be “deteriorated to the point where no train movement is allowed” in a November 2016 geometric evaluation, which was referred to in the inspection last month that prompted officials to shut down the system for repairs until March 11.

The MTA’s field guide for track inspectors says: “The qualified person(s) detecting such condition should make every effort to correct the condition immediately.”

But the trains continued running for more than a year in anticipation of track replacement scheduled for this summer.

MTA Administrator Kevin Quinn confirmed that the agency was aware of the state of its Metro tracks and decided to continue running trains on them, despite the safety standards violations.

“We made an engineering decision that the tracks were still safe to operate on. ...,” Quinn said. “Our riders were never in any danger.”

He said the MTA conducted regular visual and physical inspections of the rails. The MTA also confirmed that it slowed trains through known problem areas.

“These were rails we knew were going to need to be replaced,” he said. “They showed much more wear much sooner than anticipated.”

The safety standards violation involved the rails’ gauge face angle, a measurement of how much the trains’ wheels have chafed away at the rails. The higher the gauge face angle, the more worn — and susceptible to derailment — the track becomes.

MTA and Federal Transit Administration safety standards allow for no more than 26 degrees.

According to the inspection report released last week, the rails at 17 turns on the Baltimore Metro line exceeded 26 degrees, and two others exceeded 25 degrees, in November 2016. All nine that were measured last month were greater than 26 degrees.

The MTA’s standard is stricter than other rail lines’, Quinn noted. Some allow for angles of up to 30 or 32 degrees, he said. But the agency does not plan to change its standard, he said.

While no standard criterion exists across all rail systems, the MTA’s decision to forge ahead with service for a year — despite violating its own safety rules — was a gamble, said Gus Ubaldi, an airport and railroad engineering expert at Robson Forensic.

Ubaldi also balked at the idea that such repairs could have sneaked up on the MTA if the agency had been inspecting the rails properly and acting on inspectors’ recommendations.

“In all these years beforehand, you can start seeing what’s happening to your rail,” he said. “You can see if, over the last five years, the angle has been increasing by such-and-such. … It doesn’t happen overnight.”

Keith Millhouse, who instituted new safety measures as the board chairman of Southern California’s Metrolink after a deadly crash in Los Angeles in 2008, suggested that any MTA officials who allowed the Metro to violate its safety standards for a year should be fired.